Device for radiation of radio waves



Dec. 24, 1946. w, MCCQRDY ETAL 2,413,187

DEVICE FOR'.RADIATION OF RADIO WAVES Filed llarch e, 1942 INVENTORSATTORNEY Ammm . tenna.

Patented Dec. 24, 1946 nnvron ron RADIATION F RADIO WAVES William H.McCm-dy, Caldwell, N. J'., and John A.

Hutcheson, Baltimore, Md., assignorsto Westinghouse ElectricCorporation, East Pittsburgh, Pa., a corporation of PennsylvaniaApplication March 6, 1942, Serial No. 433,606

This invention relates to radiation of radio, waves, and moreparticularly to means for di-u rectional propagation of ultra highfrequency radio waves into space.

It is a Well established fact that radio energy may be directed in abeam, the directional characteristic being more pronounced as the wavelength employed enters the range of commonly termed micro waves, a termindicative of wave lengths of the order conveniently and normally.designated in centimeters. Ultra short waves thus characterized havebeen generated, carried to antennae situated in parabolic reflectors andthereby directed into space as relatively concentrated beams. Systems ofthe prior art have been found deficient in several respects such asinability to present voltages of desired magnitude to the antenna,losses in and mechanical difli- 2 Claims. (Cl. 250-11) generating,directing and propagating mechanism in accordance with the presentinvention; and

Fig. 1,

In the specific embodiment of the invention illustrated in said drawing,the reference numeral l0 designates in general an ultra high frequencygenerating device having an output means, such as loop ll, directlyconnected within a common evacuated enclosure therewith, an antenna orculties in transmission instrumentalities, stray .ultra highfrequency-generator to the antenna.

A further object is to utilize that energy which I heretofore was lostin transmission systems to useful. purpose. I

A still further object is to vacuum enclose the antenna, and also toprovide a common vacuum enclosure for generation and transmissionmechanisms to and with the antenna.

Again, an object of the invention is to elimi-' nate usual transmissionline ceramics and apply the generated wave energy directly to the an-Other objects of the invention are to avoid use ofcoaxial terminals,obtain a unified, compact and'complete generating and propagatingmechanism, avert stray transmission, provide for vacuum insulationthroughout, and to obtain other advantages and results which will inpart appear bydirect mention thereof hereinafter and in part byimplication from the context. 4

In the accompanying drawing wherein like numerals of reference indicatesimilar parts in the two views thereof, Figure 1 is a representationpartly in elevation and partly in section, of ultra high frequencypropagatlng'means represented by dipole i2. The

dipole 'I2 is situated substantially at the principal focus of aparabolic mirror which constitutes a specific form of directional meansl3.

In its broad aspect, the invention thus discloses a unified generating,propagatin and directing mechanism. Furthermore, the forward part of theparabolic mirror is enclosed by a cover It vacuum sealed thereto, saidcover being of'appropriate material, of which glass is an example,transparent to radio waves.

A feature of the invention resides in the unification'of the generating,propagating and directing means within a common evacuated enclosure andin utilizing the vacuum for insulative purposes. It will thus beobserved the tubular portion ii of thedipole structure is physicallyapart of the generator portion or the device and projects therefrom intothe region of the focal point of the mirror, both ends of said tubularportion being open, Those open ends communicate directly with theinterior evacuated areas of the generator and mirror, and the mirrorbeing sealed to the generator portion in spaced relation to the tube, asby a nipple ii, the vacuum space between mirror and dipole tube acts asinsulation means. Similarly the coaxial line rod I! extending from loopin the generator and projecting from the forward end of the tubularportion l5 is in vacuum and accordingly insulated from the tubularportion.

The ultra high frequency generating device in may beof suitableconstruction for the desired output. A highly effective generator isexemplifled with general showing herein or the hollowbody resonantdevice greater detailwhereof will,

be foundin co-pendlng application, Serial No 406,574, filed August 13,1941, by Ilia E. Mouromtsefi and George -M; Dinnick, and assigned to thesame assignee asthepresent case. Briefly, the

region of the opposite end, likewise on the axis of the generator, is acollector is to which elec- Figure 2 is a sectional view on line II-IIof I trons emitted from cathode l8 ultimately arrive. Between thecathode and collector and on a common axis therewith are two spacedhollow circuit members or resonators 20 within which fields, comprisingstanding electromagnetic oscillations are adapted to be set up bypassage of a beam of electrons therethrough from cathode to collector.

In accordance with usual practice, an area 2| between the resonators 20,20 is provided which is field free but through which the electrons passin their travel from the first to the second said resonators. Likewise,as usual, the resonators provide gaps or attenuated openings in whichare situated grids 22 for maintaining, as far as possible, thecontinuity of the walls of the resonators. The electrons pass frombetween one pair of such grids of the first resonator, through thefield-free space to the area between the next pair of grids of thesecond resonator, each electron completing such passage in apredetermined multiple of quarter wave lengths. After the electrons passthe grids of the second resonator, they continue into the collectorwhere remaining energy is dissipated.

As the electron beam passes through the first resonator, referred to asa buncher, a sinusoidal component corresponding to the electricaloscillations existing within the buncher is impressed on the beam ofelectrons and produces a modulation of velocity of the electrons. Themodulation of velocity causes the electrons to bunch or collect inclusters periodically and the second resonator, referred to as thecatcher, is so disposed as to absorb energy from the electrons as theypass through it. A small part of this energy is fed back throughfeed-back means 23 to the first resonator for maintainin oscillation.

Th majorpart of the energy of the second or catcher resonator istransferred by output loop I l and coaxial line to the dipole or otherantenna l2 for discharge into space as micro-wave oscillations. Sincethe antenna is within the evacuated enclosure, higher voltages thanheretofore are permitted. The close association of generator and antennaavoids power loss of transmission lines or leakage and other troublewith ceramics constituting necessary parts of transmission lines. Theuse of vacuum as insulation and physical compactness of the unitaryassembly are conducive to efiiciency.

While, for illustrative purposes, specific generating, propagating anddirecting means have been shown, each is susceptible to variation orchange, thus, a difierent oscillator than the particular resonant bodytype shown may be employed. Likewise in place of the dipole antenna,propagation of the oscillations may be by other antenna means such as anopen ended hollow wave guide. Then again, the mirror or directionalmeans may be variously constructed with the parabolic body portionthereof rendered reflective directly as a polished metal member or asglass appropriately metalized as at 24 for the purpose. Other detailchanges and modifications not specifically mentioned but obvious fromthe foregoing disclosure may be made without departing from the spiritor scope of the invention, and we do not limit ourselves in such mattersexcept as set forth in the following claims when construed in the lightof the prior art.

We claim:

1. An ultra high frequency device comprising in combination an ultrahigh frequency generator having an envelope defining a chamber therein,

'said chamber being evacuated, a second envelope protruding from thefirst said envelope, said second envelope having a rear reflecting walland a forward wall vacuum sealed therewith thereby defining a chambertherein which said chamber is also evacuated. a tubular connectionbetween said envelopes said tubular connection opening into both saidchambers and said chambers being otherwise vacuum sealed, and meanswithin the evacuated chamber of the second said envelope for propagatingoutput of said generator directly into space, said tubular connectionconstituting part of said means.

2. An ultra high frequency device comprising in combination an ultrahigh frequency generator having an envelope defining a chamber therein,said chamber being evacuated, a second envelope symmetrical about anaxis and defining a second chamber within said second envelope whichsaid second chamber is also evacuated, a tubular connection coaxial withsaid axis of the second envelope and projecting from the first chamberinwardly of the second chamber and opening into both said chambers andsaid chambers being otherwise vacuum sealed, and means for propagatingoutput of said generator directly into space in the same generaldirection as said axis, said tubular connection constituting part ofsaid means.

WILLIAM H. McCURDY. JOHN A, HUTCHESON.

